10

2012

Into the Intro: Networked Life

How does Google sell ad spaces and rank webpages? How does Netflix recommend movies, and Amazon rank products? How can you influence people on Facebook and Twitter, and can you really reach anyone in 6 steps? Why doesn’t the Internet collapse under congestion, and does it have an Achilles’ heel? Why are you charged per gigabyte for mobile data, and how can Skype and BitTorrent be free? How are cloud services so scalable, and why is WiFi slower at hotspots than at home?

Driven by 20 real-world questions about our networked lives, Networked Life: 20 Questions and Answers explores the technology behind the multi-trillion dollar Internet and wireless industries. Providing easily understandable answers for the casually curious, alongside detailed explanations for those looking for in-depth discussion, this thought-provoking book is essential reading for students in engineering, science and economics, for network industry professionals, and anyone curious about how technological and social networks really work.

How to Influence People on Facebook and Twitter

How do I infuence people on Facebook and Twitter? To study a network, we have to study both its topology (the graph) and its functionalities (tasks carried out on top of the graph). This chapter on topologydependent infuence models does indeed pursue both, as do the next two chapters.

A Short Answer
Started in October 2003 and formally founded in February 2004, Facebook has become the largest social network website, with 900 million users worldwide as of spring 2012 at the time of its IPO. Many links have been formed among these nodes, although it is not straightforward to dene how many mutual activities on each other’s wall constitute a “link.”

Founded in July 2006, Twitter attracted more than 500 million users in six years. At the end of 2011, over 250 million tweets were handled by Twitter each day. Twitter combines several functionalities into one platform: microblogging (with no more than 140 characters), group texting, and social networking (with one-way following relationships, i.e., directional links).

Facebook and Twitter are two of the most infuential communication modes, especially among young people. For example, in summer 2011’s east-coast earthquake in the USA, tweets traveled faster than the earthquake itself from Virginia to New York. They have also become a major mechanism in social organization.
In summer 2009, Twitter was a signicant force in how the Iranians organized themselves against the totalitarian regime.

There have been all kinds of attempts at figuring out

how to quantify the statistical properties of opinions on Facebook or Twitter;

how to measure the infuential power of individuals on Facebook or Twitter; and

how to leverage the knowledge of infuential power’s distribution to actually infuence people online.

Mung Chiang is the author of Networked Life (2012). Chiang is a Professor of Electrical Engineering at Princeton University and Director of the Princeton EDGE Lab. He has received the IEEE Kiyo Tomiyasu Award and a US President...